Streptomycin microbiology

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Streptomycin
STREPTOMYCIN® FDA Package Insert
Description
Clinical Pharmacology
Microbiology
Indications and Usage
Contraindications
Warnings and Precautions
Adverse Reactions
Drug Interactions
Dosage and Administration
How Supplied
Labels and Packages

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Microbiology

Streptomycin sulfate is a bactericidal antibiotic. It acts by interfering with normal protein synthesis.

Streptomycin has been shown to be active against most strains of the following organisms both in vitro and in clinical infection. (See INDICATIONS AND USAGE.):

  • Haemophilus influenzae (in respiratory, endocardial, and meningeal infections - concomitantly with another antibacterial agent)

Susceptibility Tests

Diffusion Techniques

Quantitative methods that require measurement of zone diameters give the most precise estimate of the susceptibility of bacteria to antimicrobial agents. One such standard procedure 1 which has been recommended for use with disks to test susceptibility of organisms to streptomycin uses the 10 mcg streptomycin disk. Interpretation involves the correlation of the diameter obtained in the disk test with the minimum inhibitory concentration (MIC) for streptomycin.

Reports from the laboratory giving results of the standard single disk susceptibility test with a 10 mcg streptomycin disk should be interpreted according to the following criteria:

Interpretive Criteria for Enterobacteriaceae

A report of “Susceptible” indicates that the pathogen is likely to respond to monotherapy with streptomycin. A report of “Intermediate” indicates that the result be considered equivocal, and, if the organism is not fully susceptible to alternative clinically feasible drugs, the test should be repeated. This category provides a buffer zone which prevents small uncontrolled technical factors from causing major discrepancies in interpretations. A report of “Resistant” indicates that achievable drug concentrations are unlikely to be inhibitory and other therapy should be selected.

Standardized procedures require the use of laboratory control organisms. The 10 mcg streptomycin disk should give the following zone diameter:[1]

Acceptable Control Ranges

Interpretive Criteria for Agents of Bioterrorism

References

  1. "STREPTOMYCIN INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION [X-GEN PHARMACEUTICALS, INC.]".

Adapted from the FDA Package Insert.